interface TreeHelperConfig {
    id: string;
    children: string;
    pid: string;
}

const DEFAULT_CONFIG: TreeHelperConfig = {
    id: "id",
    children: "children",
    pid: "pid"
};
export const defaultProps = {
    children: "children",
    label: "name",
    value: "id",
    isLeaf: "leaf"
};

const getConfig = (config: Partial<TreeHelperConfig>) => Object.assign({}, DEFAULT_CONFIG, config);

// tree from list
export const listToTree = <T = any>(list: any[], config: Partial<TreeHelperConfig> = {}): T[] => {
    const conf = getConfig(config) as TreeHelperConfig;
    const nodeMap = new Map();
    const result: T[] = [];
    const { id, children, pid } = conf;

    for (const node of list) {
        node[children] = node[children] || [];
        nodeMap.set(node[id], node);
    }
    for (const node of list) {
        const parent = nodeMap.get(node[pid])
        ;(parent ? parent.children : result).push(node);
    }
    return result;
};

export const treeToList = <T = any>(tree: any, config: Partial<TreeHelperConfig> = {}): T => {
    config = getConfig(config);
    const { children } = config;
    const result: any = [...tree];
    for (let i = 0; i < result.length; i++) {
        if (!result[i][children!]) continue;
        result.splice(i + 1, 0, ...result[i][children!]);
    }
    return result;
};

export const findNode = <T = any>(
    tree: any,
    func: Fn,
    config: Partial<TreeHelperConfig> = {}
): T | null => {
    config = getConfig(config);
    const { children } = config;
    const list = [...tree];
    for (const node of list) {
        if (func(node)) return node;
        node[children!] && list.push(...node[children!]);
    }
    return null;
};

export const findNodeAll = <T = any>(
    tree: any,
    func: Fn,
    config: Partial<TreeHelperConfig> = {}
): T[] => {
    config = getConfig(config);
    const { children } = config;
    const list = [...tree];
    const result: T[] = [];
    for (const node of list) {
        func(node) && result.push(node);
        node[children!] && list.push(...node[children!]);
    }
    return result;
};

export const findPath = <T = any>(
    tree: any,
    func: Fn,
    config: Partial<TreeHelperConfig> = {}
): T | T[] | null => {
    config = getConfig(config);
    const path: T[] = [];
    const list = [...tree];
    const visitedSet = new Set();
    const { children } = config;
    while (list.length) {
        const node = list[0];
        if (visitedSet.has(node)) {
            path.pop();
            list.shift();
        } else {
            visitedSet.add(node);
            node[children!] && list.unshift(...node[children!]);
            path.push(node);
            if (func(node)) {
                return path;
            }
        }
    }
    return null;
};

export const findPathAll = (tree: any, func: Fn, config: Partial<TreeHelperConfig> = {}) => {
    config = getConfig(config);
    const path: any[] = [];
    const list = [...tree];
    const result: any[] = [];
    const visitedSet = new Set(),
        { children } = config;
    while (list.length) {
        const node = list[0];
        if (visitedSet.has(node)) {
            path.pop();
            list.shift();
        } else {
            visitedSet.add(node);
            node[children!] && list.unshift(...node[children!]);
            path.push(node);
            func(node) && result.push([...path]);
        }
    }
    return result;
};

export const filter = <T = any>(
    tree: T[],
    func: (n: T) => boolean,
    config: Partial<TreeHelperConfig> = {}
): T[] => {
    config = getConfig(config);
    const children = config.children as string;

    function listFilter(list: T[]) {
        return list
            .map((node: any) => ({ ...node }))
            .filter((node) => {
                node[children] = node[children] && listFilter(node[children]);
                return func(node) || (node[children] && node[children].length);
            });
    }

    return listFilter(tree);
};

export const forEach = <T = any>(
    tree: T[],
    func: (n: T) => any,
    config: Partial<TreeHelperConfig> = {}
): void => {
    config = getConfig(config);
    const list: any[] = [...tree];
    const { children } = config;
    for (let i = 0; i < list.length; i++) {
        // func 返回true就终止遍历，避免大量节点场景下无意义循环，引起浏览器卡顿
        if (func(list[i])) {
            return;
        }
        children && list[i][children] && list.splice(i + 1, 0, ...list[i][children]);
    }
};

/**
 * @description: Extract tree specified structure
 */
export const treeMap = <T = any>(
    treeData: T[],
    opt: { children?: string; conversion: Fn }
): T[] => {
    return treeData.map((item) => treeMapEach(item, opt));
};

/**
 * @description: Extract tree specified structure
 */
export const treeMapEach = (
    data: any,
    { children = "children", conversion }: { children?: string; conversion: Fn }
) => {
    const haveChildren = Array.isArray(data[children]) && data[children].length > 0;
    const conversionData = conversion(data) || {};
    if (haveChildren) {
        return {
            ...conversionData,
            [children]: data[children].map((i: number) =>
                treeMapEach(i, {
                    children,
                    conversion
                })
            )
        };
    } else {
        return {
            ...conversionData
        };
    }
};

/**
 * 递归遍历树结构
 * @param treeDatas 树
 * @param callBack 回调
 * @param parentNode 父节点
 */
export const eachTree = (treeDatas: any[], callBack: Fn, parentNode = {}) => {
    treeDatas.forEach((element) => {
        const newNode = callBack(element, parentNode) || element;
        if (element.children) {
            eachTree(element.children, callBack, newNode);
        }
    });
};

/**
 * 构造树型结构数据
 * @param {*} data 数据源
 * @param {*} id id字段 默认 'id'
 * @param {*} parentId 父节点字段 默认 'parentId'
 * @param {*} children 孩子节点字段 默认 'children'
 */
export const handleTree = (data: any[], id?: string, parentId?: string, children?: string) => {
    if (!Array.isArray(data)) {
        console.warn("data must be an array");
        return [];
    }
    const config = {
        id: id || "id",
        parentId: parentId || "parentId",
        childrenList: children || "children"
    };

    const childrenListMap = {};
    const nodeIds = {};
    const tree: any[] = [];

    for (const d of data) {
        const parentId = d[config.parentId];
        if (childrenListMap[parentId] == null) {
            childrenListMap[parentId] = [];
        }
        nodeIds[d[config.id]] = d;
        childrenListMap[parentId].push(d);
    }

    for (const d of data) {
        const parentId = d[config.parentId];
        if (nodeIds[parentId] == null) {
            tree.push(d);
        }
    }

    for (const t of tree) {
        adaptToChildrenList(t);
    }

    function adaptToChildrenList(o) {
        if (childrenListMap[o[config.id]] !== null) {
            o[config.childrenList] = childrenListMap[o[config.id]];
        }
        if (o[config.childrenList]) {
            for (const c of o[config.childrenList]) {
                adaptToChildrenList(c);
            }
        }
    }

    return tree;
};

/**
 * 构造树型结构数据
 * @param {*} data 数据源
 * @param {*} id id字段 默认 'id'
 * @param {*} parentId 父节点字段 默认 'parentId'
 * @param {*} children 孩子节点字段 默认 'children'
 * @param {*} rootId 根Id 默认 0
 */
// @ts-ignore
export const handleTree2 = (data, id, parentId, children, rootId) => {
    id = id || "id";
    parentId = parentId || "parentId";
    // children = children || 'children'
    rootId =
        rootId ||
        Math.min(
            ...data.map((item) => {
                return item[parentId];
            })
        ) ||
        0;
    // 对源数据深度克隆
    const cloneData = JSON.parse(JSON.stringify(data));
    // 循环所有项
    const treeData = cloneData.filter((father) => {
        const branchArr = cloneData.filter((child) => {
            // 返回每一项的子级数组
            return father[id] === child[parentId];
        });
        branchArr.length > 0 ? (father.children = branchArr) : "";
        // 返回第一层
        return father[parentId] === rootId;
    });
    return treeData !== "" ? treeData : data;
};

/**
 * 校验选中的节点，是否为指定 level
 *
 * @param tree 要操作的树结构数据
 * @param nodeId 需要判断在什么层级的数据
 * @param level 检查的级别, 默认检查到二级
 * @return true 是；false 否
 */
export const checkSelectedNode = (tree: any[], nodeId: any, level = 2): boolean => {
    if (typeof tree === "undefined" || !Array.isArray(tree) || tree.length === 0) {
        console.warn("tree must be an array");
        return false;
    }

    // 校验是否是一级节点
    if (tree.some((item) => item.id === nodeId)) {
        return false;
    }

    // 递归计数
    let count = 1;

    // 深层次校验
    function performAThoroughValidation(arr: any[]): boolean {
        count += 1;
        for (const item of arr) {
            if (item.id === nodeId) {
                return true;
            } else if (typeof item.children !== "undefined" && item.children.length !== 0) {
                if (performAThoroughValidation(item.children)) {
                    return true;
                }
            }
        }
        return false;
    }

    for (const item of tree) {
        count = 1;
        if (performAThoroughValidation(item.children)) {
            // 找到后对比是否是期望的层级
            if (count >= level) {
                return true;
            }
        }
    }

    return false;
};

/**
 * 获取节点的完整结构
 * @param tree 树数据
 * @param nodeId 节点 id
 */
export const treeToString = (tree: any[], nodeId) => {
    if (typeof tree === "undefined" || !Array.isArray(tree) || tree.length === 0) {
        console.warn("tree must be an array");
        return "";
    }
    // 校验是否是一级节点
    const node = tree.find((item) => item.id === nodeId);
    if (typeof node !== "undefined") {
        return node.name;
    }
    let str = "";

    function performAThoroughValidation(arr) {
        for (const item of arr) {
            if (item.id === nodeId) {
                str += `/${item.name}`;
                return true;
            } else if (typeof item.children !== "undefined" && item.children.length !== 0) {
                str += `/${item.name}`;
                if (performAThoroughValidation(item.children)) {
                    return true;
                }
            }
        }
        return false;
    }

    for (const item of tree) {
        str = `${item.name}`;
        if (performAThoroughValidation(item.children)) {
            break;
        }
    }
    return str;
};
